AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Barford, C. C.
Right arrow Articles by Mitchell, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Barford, C. C.
Right arrow Articles by Mitchell, R.
Agricola
Right arrow Articles by Barford, C. C.
Right arrow Articles by Mitchell, R.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, March 1999, p. 989-994, Vol. 65, No. 3
0099-2240/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

Steady-State Nitrogen Isotope Effects of N2 and N2O Production in Paracoccus denitrificans

Carol C. Barford,1,* Joseph P. Montoya,2,dagger Mark A. Altabet,3 and Ralph Mitchell1

Division of Engineering and Applied Sciences1 and Biological Laboratories,2 Harvard University, Cambridge, Massachusetts 02138, and Center for Marine Science and Technology, University of Massachusetts, Dartmouth, North Dartmouth, Massachusetts 027473

Received 21 August 1998/Accepted 4 December 1998

Nitrogen stable-isotope compositions (delta 15N) can help track denitrification and N2O production in the environment, as can knowledge of the isotopic discrimination, or isotope effect, inherent to denitrification. However, the isotope effects associated with denitrification as a function of dissolved-oxygen concentration and their influence on the isotopic composition of N2O are not known. We developed a simple steady-state reactor to allow the measurement of denitrification isotope effects in Paracoccus denitrificans. With [dO2] between 0 and 1.2 µM, the N stable-isotope effects of NO3- and N2O reduction were constant at 28.6per thousand  ± 1.9per thousand and 12.9per thousand  ± 2.6per thousand , respectively (mean ± standard error, n = 5). This estimate of the isotope effect of N2O reduction is the first in an axenic denitrifying culture and places the delta 15N of denitrification-produced N2O midway between those of the nitrogenous oxide substrates and the product N2 in steady-state systems. Application of both isotope effects to N2O cycling studies is discussed.

* Corresponding author. Mailing address: Department of Earth and Planetary Sciences, Harvard University, 20 Oxford St., Cambridge, MA 02138. Phone: (617) 495-9624. Fax: (617) 495-2768. E-mail: ccb{at}io.harvard.edu.

dagger Present address: School of Biology, Georgia Institute of Technology, Atlanta, GA 30332.

Applied and Environmental Microbiology, March 1999, p. 989-994, Vol. 65, No. 3
0099-2240/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 1999 by the American Society for Microbiology. All rights reserved.